Tubular Inner Polymer Lining with a Moving Injection Head

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Solution Overview

Problem

Applying a polymeric layer to the inner surface of long, tubular structures with small inner radial dimensions is challenging, especially when the polymer is viscous, as it is difficult to fully fill the cavity due to issues with mold fit and slow flow rates.

Innovation Solution

A system and method involving a movable injecting head with nozzles that form an annular space within the tubular, allowing for longitudinal and rotational movement to ensure full 360-degree coverage, along with optional temperature control and lubrication to facilitate polymer injection and vulcanization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a mold is attached within the tubular to define a cavity for polymer injection, then the polymer layer can be applied to the inner surface, but it becomes difficult to fully fill the cavity in long tubulars with small inner radial dimensions

Engineering Contradiction:

Improvepolymer layer applicationVSAvoidcavity filling

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The injection system is divided into multiple nozzles arranged circumferentially around the tubular, with each nozzle injecting polymer into a separate sector of the annular space. This segmentation allows the polymer to be injected in multiple zones simultaneously, ensuring complete cavity filling without requiring excessive pressure or volume from a single injection point.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The injecting head is designed to move longitudinally through the tubular while polymer is injected, transforming the injection process from a static single-point operation to a dynamic multi-dimensional process. This longitudinal movement allows the polymer to be deposited progressively along the length of the tubular, ensuring complete cavity filling even in long tubulars with small radial dimensions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If viscous polymer is injected into the cavity, then the desired polymeric layer can be formed, but the flow rate is slow and cavity filling becomes even more difficult

Engineering Contradiction:

Improvepolymer layer formationVSAvoidcavity filling speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The polymer injection is segmented across multiple nozzles, distributing the total injection volume across several flow paths. This reduces the flow rate requirement per nozzle while maintaining adequate total polymer delivery, allowing viscous polymer to be injected without requiring excessively high pressures or flow rates from any single nozzle.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The injecting head moves longitudinally through the tubular during polymer injection, allowing polymer to be deposited progressively along the length of the tubular. This partial action approach ensures that polymer is injected only where needed at any given moment, reducing the total volume that must be injected simultaneously and thereby reducing the required flow rate for viscous polymer.

Inventive Principle:

Principle #16Partial or excessive action

3Manufacturing precision

If multiple molds are used to achieve full coverage, then complete 360-degree coverage can be obtained, but the device complexity and cost increase

Engineering Contradiction:

Improve360-degree coverageVSAvoidnumber of molds

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The injecting head is designed as a universal multi-functional device that combines multiple nozzles and longitudinal movement capabilities into a single unit. This single injecting head can achieve complete 360-degree coverage through its circumferential nozzle arrangement and longitudinal traversal, eliminating the need for multiple separate molds while maintaining full coverage capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The injecting head incorporates longitudinal movement capability, transforming it from a static single-point injector to a dynamic multi-position injection system. This dynamic capability allows the single injecting head to access and fill the entire annular space along the length of the tubular, achieving complete coverage without requiring multiple static molds.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables consistent and efficient application of polymer layers on long tubulars, reducing the need for multiple molds and improving bonding, while allowing for cost savings and efficient vulcanization without additional heating post-injection.

Implementation Method 1

injecting polymer through the injecting head into the annular space, and moving the polymer injecting head longitudinally relative to the tubular while injecting polymer

Methodology Applied

Scientific EffectViscous flow:

Implementation Method 2

injecting polymer through the injecting head into the annular space

Methodology Applied

Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentUS11198152B2Method of lining an inner surface of a tubular and system for doing same

Publication Date: 2021.12.14 BAKER HUGHES CO

AI summary

A method of lining an inner surface of a tubular with a polymer, includes positioning a polymer injecting head within the tubular, forming an annular space between the injecting head and an inner surface of the tubular, injecting polymer through the injecting head into the annular space, and moving the polymer injecting head longitudinally relative to the tubular while injecting polymer.